Accommodating intraocular lenses

ABSTRACT

An intraocular lens having a light-transmitting optic ( 32, 94   a   , 94   b   , 142, 216 ) comprised of a synthetic light-refractive material ( 40, 102 ) operably coupled with a flexible optic positioning member ( 34, 62, 74, 84, 100, 210 ) to refract light onto the retina in order to correct refractive errors in the eye ( 10 ). The refractive material has an index of refraction of from about 1.36 to 1.5 or higher. The optic positioning member ( 34, 62, 74, 84, 100, 210 ) is constructed of a flexible synthetic resin material such as polymethylmethacrylate and permits focusing upon objects located near to and far from the viewer. The optic ( 32, 94   a   , 94   b   , 142, 216 ) of the present invention possess greater refractive capability than optics conventionally used in IOL construction, and permits retinal receipt of the image being viewed in order to correct refractive errors.

RELATED APPLICATION

The present application is a continuation application of, and claimspriority to, U.S. patent application Ser. No. 10/280,918, filed Oct. 25,2002, now abandoned, which application is hereby incorporated byreference in it entirety for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an accommodating intraocular lensimplant (IOL), containing a refractive material therein, for surgicalreplacement of the natural crystalline lens to treat refractive errorsin the human eye.

2. Description of the Prior Art

Refractive errors in the eye affect one's ability to properly focus animage upon the retina due to a change in the refractive medium of theeye, e.g., the cornea, the natural crystalline lens, or both. Therefractive errors pertinent to this application include myopia,hyperopia, and presbyopia. A myopic lacks the ability to focus an imagelocated at a distance from the viewer because the cornea has becomeelongated, thereby increasing the eye's focal length. A hyperopic lacksthe ability to focus on objects located near the viewer because thecornea is not elongated enough or is too flat, and cannot refract lightproperly upon the retina. Instead, light entering the eye does not bendsharply enough to focus upon the retina. In contrast to myopia whereinthe image is brought to focus in front of the retina, hyperopia causesthe image to focus behind the retina. Presbyopia is another type ofrefractive error which results in the inability of the eye to focusbecause of hardening of the natural crystalline lens. The hardenednatural crystalline lens prevents focusing upon objects located near tothe viewer. Presbyopia occurs in conjunction with myopia or hyperopia.

The known treatment varies with the type of refractive error to becorrected. Each of the refractive errors may be corrected by externalspectacle lenses. Also, refractive surgery is known in the art forcorrecting the aforementioned refractive errors, and includes radialkeratotomy, astigmatic keratotomy, photoreflective keratectomy, andlaser in situ keratomileusis (LASIK). Each of the refractive surgicalmethods mentioned above involve making multiple incisions into thecornea in order to reshape it. Possible side effects of refractivesurgery include irregular astigmatism, infection, or haze formationwhich could result in permanent changes in the cornea and possible lossof best-corrected visual acuity. A possibility of under or overcorrection also exists with the aforementioned refractive surgeries.Furthermore, none of these refractive surgeries can be used to correctall of the above-referenced refractive errors.

Various IOLs have been used to treat cataracts. The first implant of anIOL within the eye to treat cataracts occurred in 1949. Thisexperimental surgery attempted to place the replacement lens in theposterior chamber of the eye behind the iris. Problems such asdislocation after implantation forced abandonment of this approach, andfor some period thereafter IOLs were implanted in the anterior chamberof the eye.

Others returned to the practice of inserting the IOL in the area of theeye posterior to the iris, known as the posterior chamber. This is thearea where the patient's natural crystalline lens is located. When theIOL is located in this natural location, substantially normal vision maybe restored to the patient, and the problems of forward displacement ofthe vitreous humor and retinal detachment encountered in anteriorchamber IOLs are less likely to occur. IOLs implanted in the posteriorchamber are disclosed in U.S. Pat. Nos. 3,718,870, 3,866,249, 3,913,148,3,925,825, 4,014,049, 4,041,552, 4,053,953, and 4,285,072. None of theseIOLs have accommodation capability.

IOLs capable of focusing offered the wearer the closest possiblesubstitute to the natural crystalline lens. U.S. Pat. No. 4,254,509 toTennant discloses an IOL which moves in an anterior direction uponcontraction of the ciliary body and which is located anterior to theiris. Although the Tennant IOL claims to possess accommodationcapabilities, it presents the same disadvantages as other anteriorchamber lenses. U.S. Pat. No. 4,253,199 to Banko approaches the problemof providing a focusable IOL in a different manner, by providing areplacement IOL of deformable material sutured to the ciliary body. ThisIOL functions in much the same manner as the natural crystalline lens,but may cause bleeding because it requires sutures.

U.S. Pat. No. 4,409,691 to Levy claims to provide an accommodating IOLpositioned within the capsule. This IOL is located in the posterior areaof the capsule and is biased toward the fovea or rear of the eye. TheLevy IOL is deficient because it requires the ciliary muscle to exertforce through the zonules on the capsule in order to compress thehaptics inward and drive the optic forward for near vision. However, theciliary muscles do not exert any force during contraction because thezonules, being flexible filaments, exert only tension, not compressionon the capsule. The natural elasticity of the IOL causes the capsule tobecome more spherical upon contraction of the ciliary muscle. Thus,there is no inward force exerted on the capsule to compress the hapticsof the Levy IOL, and therefore accommodate for near vision. Even if suchforce were somehow available, the Levy IOL's haptics are loaded inwardwhen accommodating for near vision. Since accommodation for near visionis the normal status of the capsule, the Levy IOL's haptics are loaded,reducing the fatigue life of the springlike haptics.

U.S. Pat. No. 5,674,282 to Cumming is directed towards an allegedlyaccommodating IOL for implanting within the capsule of an eye. TheCumming IOL comprises a central optic and two plate haptics which extendradially outward from diametrically opposite sides of the optic and aremovable anteriorly and posteriorly relative to the optic. However, theCumming IOL suffers from the same shortcomings as the Levy IOL in thatthe haptics are biased anteriorly by pressure from the ciliary bodies.This will eventually lead to pressure necrosis of the ciliary body.

Finally, U.S. Pat. No. 4,842,601 to Smith discloses an allegedlyaccommodating IOL having anterior and posterior members which urgeagainst the anterior and posterior walls of the capsule. The muscularaction exerted on the capsule will cause the IOL to flatten, therebychanging the focus thereof. The Smith IOL is formed of first and secondplastic lens members connected to one another adjacent their peripheraledges so as to provide a cavity therebetween. The connection between thelens members is accomplished by way of a U-shaped flange on the firstmember which forms an inwardly facing groove for receiving an outwardlyextended flange on the second member. The Smith IOL is faulty becausethe structure of the lens members makes surgical implantation thereofextremely difficult to accomplish, even for highly skilled surgeons.Furthermore, the Smith IOL requires sutures which increases the risk ofbleeding.

The IOLs discussed above replaced the opaque crystalline lenssymptomatic of cataracts through a small incision in the iris andanterior wall of the biological capsule. The IOLs for the treatment ofcataracts differed from the present invention in that the presentinvention utilizes a highly refractive material to compensate fordefects in the eye's natural refractive media, e.g, the cornea and thenatural crystalline lens.

There is a great need in the art for a lightweight IOL which can be usedto correct a variety of refractive errors in conjunction with other eyedefects which require replacement of the natural crystalline lens, suchas cataracts. This IOL should be readily insertable into the capsule andshould last for a substantial number of years without damaging any ofthe eye components.

SUMMARY OF THE INVENTION

The IOL of the present invention addresses this need because it providesa lightweight accommodating IOL, containing a highly refractive materialtherein, which is safe for long term use in an eye. The presentinvention presents a significant advance in the art because it providesan IOL for the safe and effective treatment of refractive errors incombination with other defects such as cataracts.

In more detail, the IOL comprises a resilient optic formed of a highlyrefractive material operably coupled to a flexible optic positioningmember to change shape in response to ciliary body movement, i.e.,contraction and retraction of the ciliary body. When the ciliary bodyrelaxes or retracts, it causes the zonules to elongate and exert atensional pull upon the IOL. Thus, the IOL becomes discoid in shape andallows the viewer to focus upon objects located at a distant therefrom.Similarly, when the ciliary body contracts, it becomes thicker andcauses the zonules to ease the tensional pull. Thus, the IOL becomesspheroid in shape and allows the viewer to focus upon objects locatednear to the viewer. As noted above, the optic is formed of refractivematerial that has an index of refraction of from about 1.36 to 1.5 orhigher (e.g., hydrocarbon oil, silicone oil, or silicone gel). In onetype of IOL in accordance with the invention, use is made of apre-formed capsule having a thin, continuous wall wherein the refractivematerial is enveloped.

The optic may be coupled with various optic positioning members commonlyused in IOL construction depending upon the user's eyesight. The opticmay be positioned within the capsule of the eye such that the anteriorsurface of the optic faces either the anterior or the posterior portionof the eye. When the optic is positioned to face the posterior portionof the eye, the optic will vault posteriorly in response to contractionof the ciliary body. However, the change in the radius of curvature ofthe optic will counteract the effects of the negative accommodation,i.e., movement of the optic posteriorly. The resiliency of the opticpermits a small change in radius of curvature which, when coupled withthe relatively high index of refraction of the refractive material,results in an optic having greater light-bending properties thanconventional optics.

Another preferred embodiment presents a resilient optic and a posteriorrigid optic both operably coupled on opposed sides of an opticpositioning member to change shape in response to ciliary body movement.The optics are positioned on opposite segments of the optic positioningmembers such that they share the same focal point. A similar embodimenttransposes the structure described immediately above by implanting theIOL within the eye such that the rigid optic is the anterior optic andthe resilient optic is the posterior optic.

Another embodiment of the present invention presents two opticspositioned on the same segment of the optic positioning member wherein arigid optic surrounds a resilient optic. Another embodiment similar tothe embodiment discussed immediately above, presents two opticspositioned on the same segment of the optic positioning member wherein aresilient optic surrounds a rigid optic. In this embodiment, theresilient optic changes shape in response to ciliary body movement whilethe rigid optic essentially retains its shape.

Yet another preferred embodiment of the IOL of the present inventionincludes an optic positioning member comprised of an enclosed flexiblebag having resilient fill material therein. The enclosed flexible bagpresents an anterior segment and an opposed posterior segment, eachhaving an optic. The optic positioning member is pre-formed to presentopposed optic surfaces, hence, the optics are integral with the opticpositioning member. The resilient fill material is comprised of the samerefractive material used in the above-referenced resilient opticconstruction. This embodiment also functions similarly to the IOLsdiscussed above because the anterior optic surface moves anteriorly andthe posterior optic surface moves posteriorly in response to contractionof the ciliary body. The optic surfaces of the flexible bag opticpositioning member present a small change in the radius of curvature(e.g., 5-4.6 mm) from the accommodated to disaccommodated shapes,coupled with high refractive power thereby permitting retinal receipt ofan observed image.

Another embodiment of the present invention is similar to theembodiments having opposed optics, described above, except that theoptic positioning member of this embodiment does not completely housethe refractive material. The refractive material of this IOL protrudesoutward to extend beyond the outer margins of the anterior segmentthrough an opening in the optic positioning member to define a resilientoptic. The posterior segment of the optic positioning member supports asecond posterior rigid optic positioned in opposition to the resilientoptic. The rigid optic is constructed of the same material as the opticpositioning member. The resilient material is captively retained by thesegments of the optic positioning member, but also directly contacts thebiological capsule. Contraction of the ciliary body transfers sufficientforce to the resilient and protuberant refractive material which in turndefines an optic operable to change shape in response to ciliary bodymovement. This embodiment may be constructed without the addition of asecond opposed rigid optic depending upon identifiable surgical needs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical sectional view showing an IOL of the inventionwithin the capsule of an eye, with the eye focused on an object distantfrom the viewer;

FIG. 2 is a vertical sectional view of a preferred IOL of the invention;

FIG. 3 is an anterior perspective view of the IOL of FIGS. 1 and 2;

FIG. 4 illustrates another embodiment of the invention;

FIG. 5 illustrates another embodiment of the invention;

FIG. 6 illustrates another embodiment of the invention;

FIG. 7 is a vertical sectional view of the IOL of FIG. 3 showing theoptic bonded to the anterior surface of the anterior segment of the IOLof the present invention;

FIG. 8 is a vertical sectional view of the IOL of FIG. 3 showing theoptic bonded to the posterior surface of the anterior segment of the IOLof the invention;

FIG. 9 is a vertical sectional view of another embodiment of theinvention showing the optic located at the anterior segment of the IOLand a posterior rigid optic at the posterior segment of the IOL;

FIG. 10 is a vertical sectional view of the IOL of FIG. 9 positionedwithin the eye, with the optic located at the posterior segment of theIOL and a rigid optic at the anterior segment;

FIG. 11 is a vertical sectional view of a preferred IOL of the inventionwithin the capsule of an eye, with the eye focused on an object distantfrom the viewer;

FIG. 12 is a view similar to that of FIG. 11, but illustrating the IOLin an accommodated position owing to contraction of the ciliary body;

FIG. 13 is a plan view of a preferred IOL of the invention;

FIG. 14 is a vertical sectional view taken along line 14-14 of FIG. 13;and

FIG. 15 is a greatly enlarged fragmentary of the IOL of FIGS. 11-14;

FIG. 16 is a vertical sectional view similar to that of FIGS. 7-10, butillustrating the optic constructed without an enveloping capsule;

FIG. 17 is a vertical sectional view of another embodiment of thepresent invention, illustrating a resilient optic surrounded by a rigidoptic;

FIG. 18 is a vertical sectional view of another embodiment of thepresent invention, showing an IOL of the invention within the capsule ofan eye, with the eye focused on an object located at a distance from theviewer; and

FIG. 19 is a view similar to that of FIG. 18, but illustrating the IOLin an accommodated position owing to contraction of the ciliary muscle;

FIG. 20 is a vertical sectional view showing an IOL of the inventionwithin the capsule of an eye, with the optic positioned posteriorly;

FIG. 21 is a view similar to that of FIG. 20, but illustrating the IOLin a disaccommodated position owing to retraction of the ciliary muscle;and

FIG. 22 is a vertical sectional view of another embodiment of the IOL ofthe present invention positioned within the capsule of the eye.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, the present invention is in the form ofan IOL for surgical replacement of the natural crystalline lens in thetreatment of refractive error in the human eye. FIG. 1 shows the variouscomponents of the human eye 10 pertinent to this invention. Briefly, theeye 10 includes an anterior portion 12 and a posterior portion 14. Theanterior portion 12 of the eye 10 is covered by a cornea 16 whichencloses and forms an anterior chamber 18. The anterior chamber 18contains aqueous fluid and is bounded at the rear by an iris 20. Theiris 20 opens and closes to admit appropriate quantities of light intothe inner portions of the eye 10. The eye 10 also includes a capsule 22which ordinarily contains the natural crystalline lens (which would belocated at numeral 24 in the natural, unmodified eye). The eye 10includes a ciliary muscle or body 26 having zonular fibers 28 (alsoreferred to as zonules) which are attached to the eye 10. The vitreoushumor 30 is located posterior to the capsule 22 and anterior to theretina (not pictured). The vitreous humor 30 contains vitreous fluid.

Most of the light entering the eye 10 is refracted at the air-corneainterface. The cornea 16 has an index of refraction of 1.37, and islargely responsible for refracting light into the eye 10. The light thenslightly diverges in the fluid-filled anterior chamber 18 which has anindex of refraction close to that of water, e.g., approximately 1.33,and travels to the natural crystalline lens 24. The natural crystallinelens 24 is a biconvex structure having an index of refraction of 1.4 atits center and an index of refraction of 1.38 at its outer portion. Nextto the cornea 16, the natural crystalline lens 24 is responsible forrefracting much of the light entering the human eye 10. The anteriorportion of the natural crystalline lens 24 converges light onto itsposterior portion where light is then diverged. It is at this point,that the image being viewed is inverted. The inverted image (or light)then travels into the vitreous humor 30 and through the vitreous fluid.The vitreous fluid has an index of refraction close to that of water,e.g. 1.33. After the inverted image travels through the vitreous humor30, it is brought to focus upon the retina. The retina is responsiblefor relaying electric signals to the optic nerve. The optic nerve thencarries the message to the brain which translates the inverted imageinto its upright position.

Ocular adjustments for sharp focusing of objects viewed at differentdistances are accomplished by the action of the ciliary body 26 on thecapsule 22 and natural crystalline lens 24 through the zonules 28. Theciliary body 26 contracts, allowing the capsule 22 to return to a morespherical shape for viewing objects near to the viewer. When the ciliarybody 26 retracts, to the ciliary body 26 pulls on the zonules 28 to makethe capsule 22 more discoid thus permitting objects at a distance to beviewed in proper focus. (FIG. 1) To summarize, when the eye 10 focuses,the capsule 22 changes shape to appropriately distribute the lightadmitted through the cornea 16 and the iris 20.

Referring now to FIGS. 1-22, an IOL in accordance with the inventioncomprises an optic 32 operably coupled to an optic positioning memberand implanted within the capsule 22 of the human eye 10. The IOL changesshape in response to ciliary body 26 movement. As previously noted, theoptic 32 of the present invention is formed of a highly refractivematerial. The refractive material has an index of refraction of fromabout 1.36 to 1.5 or higher. Examples of preferred refractive materialsinclude silicone oil, hydrocarbon oil, and more preferably silicone gel(available from Nusil Technology). When the refractive material used isa gel, the gel may be pre-formed into the desired optic shape andadhered onto the optic positioning member without encapsulating it.

The optic 32 may be utilized in a number of ways in a variety of opticpositioning members. The optic positioning members discussed herein arepreferably formed of any appropriate biologically inert materialconventionally used in IOL construction (e.g., elastic, synthetic resinmaterials). Examples of suitable materials include acrylates (such aspolymethylmethacrylates), silicones, and mixtures of acrylates andsilicones. It is contemplated that mixtures of silicones and acrylatescomprise both chemical mixtures, such as silicone-acrylate blends, andvarious combinations of silicones and acrylates employed to constructthe lens. It is particularly preferred that the optic positioningmembers according to the invention be constructed of a material havingan elastic memory (i.e., the material should be capable of substantiallyrecovering its original size and shape after a deforming force has beenremoved). An example of a preferred material having elastic memory isMEMORYLENS (available from Mentor Ophthalmics in California).

The preferred embodiments of the IOL of the instant invention discussedimmediately below demonstrate the variety of optic positioning membersthat may be operably coupled with the inventive optic to correctrefractive errors in the eye. The terms rigid optic and resilient opticare used herein as relative terms to one another. For instance, a rigidoptic may be any optic that is less resilient than the resilient opticof the present invention, even though the rigid optic may be moreresilient than another rigid optic. The optics of the present inventionmay be made of varying degrees of resiliency and rigidity depending uponthe materials used, therefore, the terms rigid and resilient should notbe used as limiting terms other than to convey a specific relationshipbetween two optics within the scope of this invention.

The IOL of FIGS. 1-3 [IOL 61]

The optic 32 presents a convex anterior surface 36 and a planarposterior surface 38 (hereinafter plano-convex). Although the optic 32is illustrated as plano-convex, the size and shape of the optic 32 maybe varied depending upon the user's eyesight. The optic 32 is composedof a refractive material 40 that is enveloped within a pre-formedcapsule 42 formed of a thin continuous wall 43 made of the same flexiblesynthetic resin material as the optic positioning member 34. The thinwall 43 has an anterior section 33 facing the anterior portion 12 of theeye 10 and a posterior section 41 facing the posterior portion 14 of theeye 10 respectively. (See FIG. 2) The anterior section 33 of the thinwall 43 has a thickness of from about 0.0005 to 0.025 mm, and morepreferably of about 0.004 mm, when the material used is silicone. Theposterior section 41 of the thin wall 43 has a thickness of from about0.0005 to 0.025 mm, and more preferably of about 0.003 mm, when thematerial used is silicone. One of ordinary skill in the art willappreciate that the anterior section 33 and the posterior section 41 ofthe thin wall 43 may also be constructed of uniform thickness. The optic32 may also be constructed without the refractive material housed withinthe pre-formed capsule 42 when the refractive material used is thesilicone gel material discussed above. (See FIG. 16)

The optic positioning member 34 may be integral with optic 32 or may bestructurally distinct. As illustrated, the optic positioning member 34comprises a main body 35 which includes an annular posterior segment 44with a central opening 46 and an anterior segment 37. Anterior segment37 and posterior segment 44 are located on either side of equatorialaxis 56. A plurality of circumferentially spaced, arcuate incross-section positioning legs 48 extend from the segment 44 and arejoined to the margin of optic 32, with openings 50 defined betweenadjacent pairs of the legs 48. As perhaps best seen in FIG. 2, the legs48 cooperatively present, with the optic 32, a substantially discoidshape with a central chamber 52. However, the legs 48 also define anannular equatorial segment 54 disposed on opposite sides of equatorialaxis 56. (See FIG. 2) The overall IOL 61 further presents a centralpolar axis 58 as shown. Preferably, the outside dimension of the IOL 61at the equatorial segment 48 is from about 8 to 12 mm. On the otherhand, the outside dimension along polar axis 58 is typically from about1 to 5 mm. These dimensions given immediately above, however, are onlyrepresentative of some typical dimensions within the ambit of thepresent invention. A wide range of variance necessarily exists for thedimensions of the IOLs of this invention because a wide degree ofbiological variance exists. Clearly, the dimensions of the IOLs of thepresent invention must conform to the size and shape of the eye to befitted. One of ordinary skill in the art will readily appreciate this.

The optic positioning member 34 discussed herein is configured so as tosubstantially conform with the capsule 22, particularly to theequatorial portion 27 of the capsule 22. This is shown in FIGS. 1 and 2where it will be observed that the equatorial segment 54 of the IOL 61is in substantially conforming contact with the inner surface of theequatorial portion 27 of capsule 22. This close conforming relationshipis maintained notwithstanding the extent of accommodation of IOL 61.

IOL 61 is inserted into the human eye 10 in the following manner. Anophthalmic surgeon would remove the natural crystalline lens 24 byconventional methods, leaving an opening 21 in the anterior wall 23 ofthe capsule 22. IOL 61 is then folded into a compact size for insertionin the capsule 22 through opening 21. Once inserted, the capsule 22 isfilled with fluids (e.g., saline solution) which enter the IOL 61causing IOL 61 to return to its original, non-deformed state as shown inFIG. 1. There is no need to suture the IOL 61 to the capsule 22 because,due to the size and shape of IOL 61 and conformance of the IOL 61 to thecapsule 22, the IOL 61 will not rotate or shift within the capsule 22.

Optionally, IOL 61 may be provided with a very thin membrane (not shown)in covering relationship as disclosed in U.S. patent application Ser.No. 09/940,018, filed Aug. 27, 2001, which is incorporated by referenceherein. It is contemplated that the membrane would be formed of the samesynthetic resin as the optic positioning member 34 but would be muchthinner (on the order of a few thousandths of an inch) than theremainder of the optic positioning member 34. The purpose of themembrane is to prevent or at least impede the passage of migratory cellsthrough openings within the IOL 61 and into the inner chamber of the IOL61.

Furthermore, optic positioning member 34 construction is disclosed inpreviously filed application for U.S. patent Ser. No. 10/280,937entitled Accommodating Intraocular Lens Implant and U.S. patent Ser. No.09/940,018 entitled Intraocular Lens Implant Having Eye AccommodatingCapabilities both to the same applicant, which are hereby incorporatedby reference herein as is necessary for a full and completeunderstanding of the present invention.

Implantation of the inventive IOL 61 restores normal vision by providingan optic 32 formed of highly refractive material capable of bendinglight onto the retina. After implantation of the IOL 61 in the human eye10, light refracts at the air-cornea interface in the same manner as thenatural human eye 10. The light travels through the fluid-filledanterior chamber 18 and onto the optic 32. The radius of curvature ofthe optic 32 changes in response to ciliary body 26 movement, thusaffecting the optic's 32 refractive capabilities.

Not only does the IOL 61 project an observed image onto the retina, butit also accommodates in response to action of the ciliary body 26 inconnection with the zonules 28 to view objects located both near and farfrom the viewer. When the viewer is observing an image located at adistance, the sensory cells within the retina signal the ciliary body 26to relax, thus pulling on the zonules 28 to make the capsule 22 morediscoid as shown in FIG. 1. In doing so, the polar dimension of thecapsule 22 narrows, subsequently causing the polar dimension of the IOL61 to similarly narrow. Those ordinarily skilled in the art willappreciate that the optic positioning member 34 is operably coupled withthe optic 32 of the present invention to change shape in response tociliary body 26 movement. In this regard, the movement of the ciliarybody 26 causes the optic 32 to move posteriorly and anteriorly,respectively. Contraction of the ciliary body 26 and subsequentrelaxation of the zonules 28 will cause the optic 32 to vaultanteriorly.

The IOL 61 of the present invention typically has a diopter value offrom about 16 to 26. The diopter value of a lens is defined as thereciprocal of the focal length in meters:Diopter=1/focal length (m)Focal length is the distance from the center of the lens to the objectbeing viewed. The focal length must decrease as magnification increases.The diopter value expresses the refractive capacity of a lens which isassociated with the radius of curvature of the optics. Generally, anincreased diopter value indicates that the optic is thicker and also hasa lesser radius of curvature thus possessing greater light-bendingcapability.The IOL of FIG. 4 [IOL 60]

The IOL 60 is similar to IOL 61 illustrated in FIGS. 1-3. IOL 60comprises an optic positioning member 62 wherein the optic positioningmember 62 presents an anterior segment 66 and a posterior segment 68each having a central opening therein 67, 69. A plurality ofindividually continuous, circumferentially spaced, arcuate incross-section positioning legs 64 extend from anterior segment 66 andare joined to the margin of optic 32, with openings 71 defined betweenadjacent pairs of the legs 64, by haptic arms 72. The haptic arms 72extend between the posterior segment 68 to the margin of the optic 32.The haptic arms 72 join the optic 32 and the optic positioning member62. This embodiment is similar to IOL 61 in that it may also beconstructed with a thin membrane as disclosed in U.S. patent applicationSer. No. 09/940,018, filed Aug. 27, 2001 which has been incorporated byreference herein.

In this embodiment, it is important that the posterior segment 68 of theoptic positioning member 62 not be fixed with respect to the posteriorportion of the capsule 22. This would not be the case if the posteriorsegment 68 was continuously connected with the positioning legs 64.While not shown in the figures, the anterior segment 66 may becontinuously connected by an annular haptic. IOL 60 is implanted andoperates in the same manner as IOL 61. The IOL 60 of the presentinvention typically has a diopter value of from about 16 to 26.

Furthermore, optic positioning member 62 construction is disclosed inpreviously filed application for U.S. patent Ser. No. 10/280,937entitled Accommodating Intraocular Lens Implant and U.S. patent Ser. No.09/940,018 entitled Intraocular Lens Implant Having Eye AccommodatingCapabilities both to the same applicant, which are hereby incorporatedby reference herein as is necessary for a full and completeunderstanding of the present invention.

The IOL of FIG. 5 [IOL 60 a]

A preferred IOL 60 a according to the invention is illustrated in FIG.5. Similar to the IOL 60 embodiment described above, this IOL 60 acomprises an optic 32 and an optic positioning member 74 presenting ananterior segment 66 a and a posterior segment 68 a. A plurality ofcircumferentially spaced, arcuate in cross-section positioning legs 76extend from the anterior segment 66 a to the optic 32. The haptic arm 72a extends posteriorly from the anterior segment 66 a to the optic 32. Ina further preferred embodiment of IOL 60 a, the optic 32 may beconnected to the optic positioning member 74 via a plurality of hapticarms (not shown). The plurality of haptic arms are disposed at variouslocations about anterior segment 66 a and extend posteriorly towards theoptic 32. The plurality of legs 76 are continuously attached to eachother through continuous sections 80 presenting annular orifices 82therethrough. This embodiment is similar to IOL 61 and 60 in that it mayalso be constructed with a thin membrane as disclosed in U.S. patentapplication Ser. No. 09/940,018, filed Aug. 27, 2001 which has beenincorporated by reference herein.

IOL 60 a is implanted and operates in a similar manner to IOLs 61 and60. The IOL 60 a of the present invention typically has a diopter valueof from about 16 to 26. Furthermore, the construction of opticpositioning member 74 is disclosed in previously filed application forU.S. patent Ser. No. 10/280,937 entitled Accommodating Intraocular LensImplant and U.S. patent Ser. No. 09/940,018 entitled Intraocular LensImplant Having Eye Accommodating Capabilities both to the sameapplicant, which are hereby incorporated by reference herein as isnecessary for a full and complete understanding of the presentinvention.

The IOL of FIG. 6 [IOL 60 b]

FIG. 6 depicts yet another preferred IOL 60 b according to theinvention. This IOL 60 b also comprises an optic 32 and an opticpositioning member 84 presenting an anterior segment 66 b and aposterior segment 68 b. The optic positioning member 84 furthercomprises a plurality of circumferentially spaced, arcuate incross-section positioning legs 88 having openings 86 therein betweenadjacent pairs of legs 88. In essence, the IOL 60 b is configured inmuch the same fashion as the IOL 60, with the exception that a pluralityof haptic arms 72 b extend from equatorial segment 54 toward the optic32. When the IOL 60 b is in its original, non-compressed state, thehaptic arms 72 b are vaulted slightly toward anterior segment 66 b.

This embodiment is similar to IOL 61, 60, and 60 a in that it may alsobe constructed with a thin membrane as disclosed in U.S. patentapplication Ser. No. 09/940,018, filed Aug. 27, 2001 which has beenincorporated by reference herein.

IOL 60 b is implanted and operates in a similar manner to IOLs 61, 60and 60 a. The IOL 60 b of the present invention typically has a dioptervalue of from about 16 to 26. Furthermore, the construction of opticpositioning member 84 is disclosed in previously filed application forU.S. patent Ser. No. 10/280,937 entitled Accommodating Intraocular LensImplant and U.S. patent Ser. No. 09/940,018 entitled Intraocular LensImplant Having Eye Accommodating Capabilities both to the sameapplicant, which are hereby incorporated by reference herein as isnecessary for a full and complete understanding of the presentinvention.

The IOL of FIGS. 7 and 8 [IOL 61 d]

IOL 61 d is another embodiment of the present invention. IOL 61 dpresents a variation upon the structure of IOL 61 wherein the optic 32is bound to either the anterior surface 31(a) or the posterior surface31(b) of the optic positioning member 34. IOL 61 d operates in and isimplanted in the same manner as IOL 61.

Notably, IOL 61 d illustrated in FIGS. 7 and 8 comprises a liquidrefractive material 40 enveloped within the capsule 42. The indices ofrefraction of the wall 43 and the refractive material 40 may be variedto satiate surgical, medical, or manufacturing needs.

The IOL of FIGS. 9 and 10 [IOL 61 a]

IOL 61 a differs from the embodiments discussed thus far in that whilethe optic 32 is operably coupled to the anterior segment 37 of the opticpositioning member, a second rigid optic 90 is operably coupled to theposterior segment 44. The optics 32, 90 are positioned on opposedsegments 37, 44 of the optic positioning member such that the optics 32,90 share the same optical axis. Opposition or opposed in this context isused consistently in this application to mean positioned on the oppositeside of equatorial axis 56(a) such that both optics share substantiallythe same optic axis, and are aligned such that the IOL providesundistorted vision. The posterior optic 90 is made of the same materialas the optic positioning member 34, however, one of ordinary skill inthe art will recognize that the posterior optic 90 may be constructed ofthe inventive refractive material as well.

This embodiment is implanted and operates in essentially the same manneras the IOLs discussed thus far, but differs because it includes a secondopposed rigid optic 90. The anterior optic 32 converges light upon theposterior optic 90. The posterior optic 90, in turn, diverges the lightonto the retina. Any irregularities in the cornea 16 or the naturalcrystalline lens 24 are counteracted by the highly refractive material102, thereby bringing the image to focus upon the retina. Thisembodiment also accommodates in response to ciliary body 26 movement.When the ciliary body 26 contracts, the IOL 61 a assumes a spheroidshape. The anterior optic 32 moves anteriorly whereas the posterioroptic 90 moves posteriorly. When the ciliary body 26 retracts, thezonules 28 exert a tensional pull upon the IOL to change the IOL to adiscoid shape. The anterior optic 32 moves posteriorly whereas theposterior optic 90 moves anteriorly. The IOL 61 a of the presentinvention typically has a diopter value of from about 16 to 26.

IOL 61 a may also be positioned within the eye 10 such that the rigidoptic 90 is located anteriorly and the optic 32 is positionedposteriorly as illustrated in FIG. 10. When the IOL 61 a is positionedwithin the eye 10 in this manner, the IOL 61 has a combined totalrefraction of about 16 to 26 diopters.

The IOL of FIGS. 11-15 [IOL 92]

Another preferred embodiment of the present invention includes ananterior optic 94 a and a posterior optic surface 96 a integral with anoptic positioning member 98, such that the IOL 92 presents a unitarystructure for implantation within the capsule 22 of the human eye 10.(See FIG. 11) IOL 92 comprises a main body presenting a pre-formedenclosed flexible bag 100 having a resilient fill material 102(a)therein. The pre-formed enclosed flexible bag 100 may also be filledwith other refractive media disclosed herein. Flexible bag 100 comprisesan anterior segment 104, and a posterior segment 106. Flexible bagfurther includes wall 112 which, when viewed in cross section, forms andextends radially from an anterior arcuate wall segment 94 and convergesupon the posterior segment 106 of the IOL 92 to form an opposingposterior arcuate wall segment 96. The opposing arcuate wall segments94, 96 define opposed anterior and posterior optic surfaces 94 a, 96 awhen cavity 114 of enclosed flexible bag 100 is filled with material102(a). Although the terminology ‘optic surface’ is used herein todescribe surfaces 94 a and 96 a, these surfaces 94 a, 96 a, operatefunctionally as optics. Therefore, the term optic may be usedinterchangeably to describe optic surfaces 94 a, 96 a within theremainder of this disclosure.

The anterior optic surface 94 a and the posterior optic surface 96 ahave a combined radius of curvature of from about 16 to 26 diopters.(See FIG. 11) The anterior optic surface 94 a and the posterior opticsurface 96 a are both illustrated as convex in shape. When viewed incross-section, anterior segment 94 and posterior segment 96 areconnected by a pair of opposed arcuate equatorial segments 124 a asshown in FIG. 14.

Wall 112 includes a fill aperture 118 with a plug therein closing theaperture 118. Although aperture 118 is illustrated at location 120 ofthe IOL 92, the aperture 118 can be formed at any location on the IOL92. Preferably the IOL 92 will have an outer equatorial diameter(distance of IOL 92 taken through equatorial axis 124) of from about 8to 12 mm. (See FIG. 13) Preferably the IOL will have an outsidedimension through the central polar axis 122 of from about 2 to 5 mm.(See FIG. 13)

An ophthalmologist fills cavity 114 with material 102(a) prior tosurgical implantation of the IOL 92 within the human eye 10 by insertingthe material 102(a) through the aperture 118. After cavity 114 isfilled, the aperture 118 is sealed. The ophthalmologist removes thenatural crystalline lens 24 by conventional methods, leaving an openingin the anterior wall 23(a) of the capsule 22. The IOL 92 is folded aninserted within the capsule 22 through the opening. Implantation of theIOL 92 does not require suturing of the eye 10 be because the instantIOL 92 is capable of being implanted through a small opening in thecapsule 22.

IOL 92 operates in the same manner as IOL 61 a because IOL 92 includesopposed optic surfaces 94, 96. Anterior optic 94 converges light uponthe posterior optic 96, which in turn, diverges light onto the retina.The IOL 92 responds to contraction of the ciliary body 26 by assuming aspheroid shape.

IOL of FIG. 16 [IOL 61]

FIG. 16 illustrates optic 32 of the inventive IOL 61 formed from aresilient silicone gel material. Therefore, the IOL 61 of FIG. 16 doesnot depict the refractive material enveloped within a pre-formed capsule42 having a thin continuous wall 43. The capsule 42 is not needed whenthe refractive material is formed from a resilient, shape-retainingsynthetic material such as the silicone gel discussed above.

IOL of FIG. 17 [IOL 61 c]

Another preferred embodiment of the present invention includes an opticpositioning member 34 operably coupled with two optics 142, 144 tochange shape in response to ciliary body 26 movement. IOL 61 c includesa resilient optic 142 surrounded by a rigid optic 144. The resilientoptic 142 is formed of the refractive material discussed above. Therigid optic 144 is formed of the same material as the optic positioningmember 34. Both optics 142, 144 are housed within a pre-formed capsule42 as described in connection with IOL 61.

IOL 61 c operates in a similar manner as the embodiments discussed sofar, but differs in that the resilient optic 142 surrounded by the rigidoptic 144 maintains a constant volume in response to ciliary body 26movement. The constant volume of the resilient optic 142 coupled withthe relatively high refractive index of the refractive materialcontained therein confers increased light-bending properties upon theresilient optic 142.

IOL of FIGS. 18 and 19 [IOL 200]

Another preferred embodiment is an IOL 200 having an annular opticpositioning member 210 presenting spaced-apart arcuate anterior 212 andposterior segments 214. The IOL 200 further includes an anteriorresilient optic 216 and a posterior rigid optic 218 operably coupled tothe optic positioning member 210 to change shape in response to ciliarybody 26 movement.

The anterior segment 212 of the optic positioning member 210 contains anopening 220 of from about 7 to 3 mm, and more preferably of about 4 mmwide. The anterior segment 212 further includes an outer margin 222 andan inner margin 224. The outer margin 222 is defined as the anteriorportion of the anterior segment 212, or that portion of the segment 212closest to the iris 20. The posterior segment 214 also includes an innermargin 226 and an outer margin 228 wherein the inner margin 226 of theposterior segment 214 is the margin closest to the iris 20 as well. Thespace between the anterior segment 212 and the posterior segment 214 isoccupied by refractive material such that the refractive material isadjacent to the inner margins 224, 226 of the segments 212, 214. Therefractive material protrudes beyond the outer margin 222 of theanterior segment 212. This protrusion defines the resilient optic 216.The refractive material used herein is the refractive silicone geldiscussed above. The silicone gel refractive material may be pre-formedinto the desired shape and connected, by posts, to the segments 212, 214of the optic positioning member 210. The refractive material may also beencompassed within a bladder which is also similarly connected to thesegments 212, 214. In this case, the refractive material used may alsobe a liquid.

The IOL 200 may further include a second rigid optic 218 opposed toresilient optic 216. The rigid optic 218 is made of the same material asthe optic positioning member 210 and is supported by the posteriorsegment 214. As mentioned above, the space between the segments 212, 214is occupied by refractive material. This IOL 200 differs from the otherembodiments discussed herein because the refractive material is notcompletely contained by the optic positioning member 210 in addition tothe optic 216 defining protrusion which extends beyond the outer margin222 of the anterior segment 212. The refractive material is positionedbetween the two segments 212, 214 such that the refractive materialcomes into direct contact with the biological capsule 22 at locations230.

IOL 200 is implanted in the same manner as IOL 61 after IOL 200 isassembled, and operates in a similar manner to the other IOLs havingopposed optics discussed herein. Contraction of the ciliary body 26 andsubsequent relaxation of the zonules 28 exerts force upon the refractivematerial causing the material to protrude outward to extend beyond theouter margin 222 of the anterior segment 212. When the ciliary body 26retracts, the zonules 28 exert a tensional pull upon the capsule 22, andthe refractive material assumes its more flattened shape to view objectslocated at a distance.

IOL of FIGS. 20 and 21 [IOL 61 b]

The IOL 61 b illustrated in FIGS. 20 and 21 demonstrate yet anotherpreferred embodiment of the invention. FIGS. 20 and 21 demonstrate anyof the IOLs of FIGS. 1-8 and 16 discussed above positioned within theeye 10 such that the optic 32 is positioned posteriorly. One of skill inthe art would readily appreciate that although FIGS. 20 and 21illustrate any of the IOLs of FIGS. 1-8 and 16 in the vertical sectionalview, any of the IOLs of the present invention may be positioned suchthat the anterior optic faces posteriorly. FIG. 20 illustrates the IOLof the present invention in the accommodated shape. FIG. 21 illustratesthe IOL in the disaccommodated shape.

IOL of FIG. 22 [IOL 61 e]

IOL 61 e illustrated in FIG. 22 is similar to IOL 61 c illustrated inFIG. 17. IOL 61 e differs from IOL 61 c in that the resilient optic 142a surrounds the rigid optic 144 a. FIG. 22 illustrates IOL 61 epositioned posteriorly in the capsule 22 of the eye 10. The resilientoptic 142 a changes shape in response to ciliary body 26 movement. Thechange in curvature of the resilient optic 142 a provides about 3diopters of convergence while the rigid optic 144 a essentiallymaintains its shape.

Although the invention has been described with reference to thepreferred embodiment illustrated in the attached drawing figures, it isnoted that equivalents may be employed and substitutions made hereinwithout departing from the scope of the invention as recited in theclaims. For example, the IOLs of the present invention may all beconstructed in the disaccommodated or accommodated shapes. Also, whilethe foregoing method of inserting the IOL in the capsule 22 presumedthat a portion of the anterior wall 23(a) of the capsule 22 would beremoved with the natural crystalline lens 24, it will be appreciatedthat it may be possible to insert the IOL an incision in the posteriorwall 53 of the capsule 22. Furthermore, while the foregoing descriptiondiscloses that the IOL could be utilized to correct refractive error,the IOL may be used in any situation where the natural crystalline lens24 should be replaced. For example, the IOL may be used to correctmyopia, hyperopia, presbyopia, cataracts, or a combination thereof.Various refractive media may be used to fill cavity 114 of IOL dependingupon the desired index of refraction.

What is claimed:
 1. An accommodating intraocular lens (IOL), comprising:an anterior, resilient optic disposed about an optical axis; aposterior, rigid optic disposed about the optical axis, the rigid opticbeing less resilient than the resilient optic; an optic positioningmember comprising a plurality of arcuate in cross-section positioninglegs, each positioning leg with an equatorial segment disposed along anequatorial plane and configured to conform with an inner surface of anequatorial portion of a capsule of an eye, each positioning legincluding anterior and posterior segments disposed on opposite sides ofthe equatorial segment, each anterior segment being coupled to theresilient optic by a haptic arm extending posteriorly from the anteriorsegment to the periphery of the resilient optic and each posteriorsegment being coupled to the periphery of the rigid optic; wherein theplurality of positioning legs are circumferentially spaced around theresilient optic and rigid optic forming a generally annular shape; andwherein, in response to ciliary body movement of an eye, the resilientoptic and the rigid optic move in opposite directions from one anotheralong the optical axis, wherein the positioning member is operable forchanging the radius of curvature of the resilient optic in response tociliary body movement so as to affect the refractive power of theresilient optic, wherein the positioning legs and the opticscooperatively present a spheroid shape, and wherein the resilient opticcomprises a gel material enveloped within a pre-formed capsule having athin continuous wall.
 2. The intraocular lens of claim 1, wherein theresilient and the rigid optic are made of the same material as the opticpositioning member.
 3. The intraocular lens of claim 1, wherein theresilient optic or the rigid optic is made of the same material as theoptic positioning member.
 4. The intraocular lens of claim 1, whereinthe resilient optic or the rigid optic comprises a resilient siliconegel material.